Yellow dye.



snares PAUL VOLKMANN, F ELBERFELD, GERMANY, ASSIGNOR T0 FARBENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERIEELD, GERMANY, .A. CORPORATION OF GERMANY.

YELLOW DYE.

No Drawing.

Specification of Letters Patent. Patented Oct. 18, 1910. Application filed January 12, 1910. Serial No. 531,730.

To all whom, it may concern:

Be it known that I, PAUL VOLKMANN, doctor of philosophy, chemist, citizen of the German Empire, residing at Elberfeld, Germany, have invented new and useful Improvements in Yellow Dyes, of which the parts of sulfuric acid (60 B.) To this mixture 106 parts of,the' sodium salt of dioxytartaric acid are added. The mixture is stirred for 1 hour and is then boiled for 2 hours. The dye is salted out, filtered off, mixed with sodium carbonate to make the neutral sodium salt and dried.

It is in the shape of its sodium salt a yellow powder soluble-in concentrated sulfuric acid with a yellow color. Upon reduction with stannous chlorid and hydro-- chloric acid the dye is decomposed, anilinsulfonic acid and 1-sulfophenyl-3carb0xy- 4-amino-5-pyrazolone is obtained. It produces on wool bright greenish-yellow level shades, fast to light.

, The herein described new coloring matter obtainable from pl1enylhydrazinorthoand para-sulfonic acid and dioxytartarie acid,

which is in dry state in the shape of its sodium salt a yellow powder soluble in concentrated sulfuric acid with a yellow color;

yielding upon reduction with stannous chlo-' rid and hydrochloric acid anilin sulfonic acid and l-sulfophenyl-3-carboxy-4-an1ino: 5-pyrazolone; and dyeing wool bright green ish-yellowv shades, substantially as described.

In testimony whereof'I have hereunto set my hand in the presence of two subscribing witnesses. Y

PAUL VOLKMANN. 1. 8;

W'itnesses:

O'r'ro KiiNrc, CHAS. J. WRIGHT. 

